15697391 has 2 divisors, whose sum is σ = 15697392. Its totient is φ = 15697390.

The previous prime is 15697373. The next prime is 15697393. The reversal of 15697391 is 19379651.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 15697391 - 2¹⁰ = 15696367 is a prime.

Together with 15697393, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15697393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7848695 + 7848696.

It is an arithmetic number, because the mean of its divisors is an integer number (7848696).

Almost surely, 2^15697391 is an apocalyptic number.

15697391 is a deficient number, since it is larger than the sum of its proper divisors (1).

15697391 is an equidigital number, since it uses as much as digits as its factorization.

15697391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51030, while the sum is 41.

The square root of 15697391 is about 3961.9933114532. The cubic root of 15697391 is about 250.3854906158.

The spelling of 15697391 in words is "fifteen million, six hundred ninety-seven thousand, three hundred ninety-one".